galileo galilei (gg) system budgets report drl/drd: del …eotvos.dm.unipi.it/temp/old/gg prr...

CONTROLLED DISTRIBUTION REFERENCE : DATE :

SD-RP-AI-0628 June 09

ISSUE : 01 PAGE : 1/34

All rights reserved, 2007, Thales Alenia Space

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CONTROLLED DISTRIBUTION

GALILEO GALILEI (GG)

SYSTEM BUDGETS REPORT

DRL/DRD: DEL-33

Written by Responsibility

L. Perachino Author

Verified by

n.a. Checker

Approved by

Product Assurance

Configuration Control

Design Engineer

System Engineering Manager

A. Anselmi Study Manager

Documentation Manager

R. Cavaglià

The validations evidence are kept through the documentation management system.





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ISSUE DATE § CHANGE RECORDS AUTHOR

01 08-Jun-09 First issue submitted to PRR





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TABLE OF CONTENTS

1. SCOPE AND PURPOSE ..................................................................................................5

2. REFERENCES .................................................................................................................6

2.1 Applicable Documents ................................................................................................................... 6

2.2 Standards ....................................................................................................................................... 6

2.3 ASI Reference Documents.............................................................................................................. 6

2.4 GG Phase A2 Study Notes .............................................................................................................. 6

3. MASS BUDGETS.............................................................................................................8

3.1 System Mass Budget ...................................................................................................................... 8

3.2 PGB Mass Budgets......................................................................................................................... 9 3.2.1 Detailed Experiment Mechanics Mass Budget ................................................................................ 9

3.3 SVM Mass Budget......................................................................................................................... 10

3.4 Propellant Mass Budgets.............................................................................................................. 11 3.4.1 Attitude Control propellant mass budget ....................................................................................... 11 3.4.2 FEEP propellant mass budget ..................................................................................................... 11 3.4.3 CGPS propellant mass budget (alternative) .................................................................................. 11

4. MASS PROPERTIES......................................................................................................12

4.1 Centre of Mass, Direction cosines of the Principal Axes and Inertia Matrix ................................. 12

5. POWER BUDGET ..........................................................................................................15

5.1 System Power Budget .................................................................................................................. 15

5.2 Payload Power Budget ................................................................................................................. 16

5.3 SVM Power Budget ....................................................................................................................... 16

6. DATA RATE BUDGET ...................................................................................................19

7. RF LINK BUDGETS .......................................................................................................20

8. POINTING BUDGET.......................................................................................................33





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LIST OF TABLES TABLE 3.1-1: LAUNCH MASS BUDGET...............................................................................................................................................8 TABLE 3.2-1: PGB MECHANICS MASS BUDGET .................................................................................................................................9 TABLE 3.3-1: SVM MASS BUDGET..................................................................................................................................................10 TABLE 4.1-1: MASS PROPERTIES FOR THE FULL GG SPACECRAFT..................................................................................................12 TABLE 4.1-2: MASS PROPERTIES FOR THE GG SPACECRAFT WITHOUT THE PGB ASSEMBLY .........................................................13 TABLE 4.1-3: MASS PROPERTIES FOR THE PGB ASSEMBLY WITHOUT THE PROOF MASSES.............................................................13 TABLE 4.1-4: MASS PROPERTIES FOR THE OUTER PROOF MASS ......................................................................................................14 TABLE 4.1-5: MASS PROPERTIES FOR THE INNER PROOF MASS .......................................................................................................14 TABLE 5.1-1: SATELLITE POWER BUDGET......................................................................................................................................15 TABLE 5.2-1: PAYLOAD POWER BUDGET ........................................................................................................................................16 TABLE 5.3-1: SVM POWER BUDGET ...............................................................................................................................................16 TABLE 5.3-2: POWER DELIVERED BY THE SOLAR ARRAY AT BOL AND AFTER 6 YEARS. .................................................................17 TABLE 5.3-1: GG DATA RATE BUDGET ...........................................................................................................................................19 TABLE 5.3-1: SPIN AXIS POINTING ERROR AT SPIN-UP COMPLETION ...............................................................................................33 TABLE 5.3-2: SPIN AXIS POINTING ERROR AFTER ONE YEAR MISSION WITH 1 FAILED THRUSTER ...................................................33

LIST OF FIGURES FIGURE 5.3-1: PCDU SUNLIGHT POWER CONSUMPTION .................................................................................................................18 FIGURE 5.3-2: PCDU ECLIPSE POWER CONSUMPTION.....................................................................................................................18





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1. SCOPE AND PURPOSE

This document is submitted in partial fulfilment of Work Package 1A-ADA of the GG Phase A2 Study (DRL item DEL-33). The purpose of the document is to provide the budget status of the reference GG configuration, documented in [RD-4].





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2. REFERENCES

2.1 Applicable Documents

[AD 1] ASI, “Progetto Galileo Galilei-GG Fase A-2, Capitolato Tecnico”, DC-IPC-2007-082, Rev. B, 10-10-2007 and applicable documents defined therein

2.2 Standards

[SD 1] ECSS-M-00-02A, Space Project Management – Tailoring of Space Standards, 25 April 2000

[SD 2] ECSS-E-ST-10C, Space Engineering - System Engineering General Requirements, 6 March 2009

[SD 3] ECSS-E-10-02A, Space Engineering – Verification

[SD 4] ECSS-Q-00A, Space Product Assurance - Policy and Principles, and related Level 2 standards.

2.3 ASI Reference Documents

[RD 1] GG Phase A Study Report, Nov. 1998, revised Jan. 2000, available at: http://eotvos.dm.unipi.it/nobili/ggweb/phaseA/index.html

[RD 2] Supplement to GG Phase A Study (GG in sun-synchronous Orbit) “Galileo Galilei-GG”: design, requirements, error budget and significance of the ground prototype”, A.M. Nobili et al., Physics Letters A 318 (2003) 172–183, available at: http://eotvos.dm.unipi.it/nobili/documents/generalpapers/GG_PLA2003.pdf

[RD 3] A. Nobili, DEL001: GG Science Requirements, Pisa, September 2008

2.4 GG Phase A2 Study Notes

[RD 4] SD-RP-AI-0625, GG Final Report / Satellite Detailed Architecture Report, Issue 1

[RD 5] SD-RP-AI-0626, GG Phase A2 Study Executive Summary, Issue 1

[RD 6] SD-TN-AI-1163, GG Experiment Concept and Requirements Document, Issue 3

[RD 7] SD-RP-AI-0620, GG System Performance Report, Issue 2

[RD 8] SD-TN-AI-1167, GG Mission Requirements Document, Issue 2

[RD 9] SD-RP-AI-0590, GG System Concept Report (Mission Description Document), Issue 3

[RD 10] SD-SY-AI-0014, GG System Functional Specification and Preliminary System Technical Specification, Issue 1

[RD 11] SD-RP-AI-0631, GG Consolidated Mission Description Document, Issue 1

[RD 12] SD-TN-AI-1168, GG Mission Analysis Report, Issue 2

[RD 13] DTM, GG Structure Design and Analysis Report , Issue 1





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[RD 14] SD-RP-AI-0627, GG Thermal Design and Analysis Report, Issue 1

[RD 15] SD-RP-AI-0268, GG System Budgets Report, Issue 1

[RD 16] SD-RP-AI-0621, Technical Report on Drag and Attitude Control, Issue 2

[RD 17] TL25033, Payload Architectures and Trade-Off Report, Issue 3

[RD 18] SD-RP-AI-0629, Technical Report on Simulators, Issue 1

[RD 19] GG.ALT.TN.2003, FEEP Microthruster System Technical Report, Issue 1

[RD 20] TASI-FI-44/09, Cold Gas Micro Thruster System for Galileo Galilei (GG) Spacecraft - Technical Report, Issue 1, May 2009

[RD 21] SD-RP-AI-0630, Spin Sensor Design, Development and Test Report, Issue 1

[RD 22] SD-TN-AI-1169, GG Launcher Identification and Compatibility Analysis Report, Issue 1

[RD 23] ALTEC-AD-001, GG Ground Segment Architecture and Design Report, Issue 1

[RD 24] SD-TN-AI-1218, GG Preliminary Product Tree, Issue 1

[RD 25] SD-PL-AI-0227, GG System Engineering Plan (SEP), Issue 2

[RD 26] TAS-I, Payload Development and Verification Plan, Issue 1

[RD 27] SD-PL-AI-0228, GG System Verification and Validation Plan, Issue 1

[RD 28] SD-TN-AI-1219, Report on Frequency Management Issues, Issue 1

[RD 29] SD-RP-AI-0632, GG Mission Risk Assessment And Mitigation Strategies Report, Issue 1

[RD 30] SD-RP-AI-0633, Report on Mission Costs Estimates, Issue 1





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3. MASS BUDGETS

3.1 System Mass Budget

Galileo Galilei

Target Spacecraft Mass at Launch 1000,00 kgBelow Mass Target by: 482,18 kg

Without Margin Margin Total % of TotalDry mass contributions % kg kg

Structure 104,61 kg 18,09 18,92 123,53 23,86Thermal Control 8,70 kg 20,00 1,74 10,44 2,02Communications 9,60 kg 10,00 0,96 10,56 2,04Data Handling 16,00 kg 20,00 3,20 19,20 3,71AOCS 5,92 kg 13,11 0,78 6,69 1,29Propulsion 37,66 kg 13,95 5,26 42,92 8,29Power 57,68 kg 14,82 8,55 66,23 12,79Harness 12,50 kg 20,00 2,50 15,00 2,90Payload 55,34 kg 12,77 7,07 62,41 12,05Total Dry(excl.adapter) 308,01 356,98 kgSystem margin (excl.adapter) 20,00 % 71,40 kgTotal Dry with margin (excl.adapter) 428,38 kg

Other contributionsWet mass contributions

Propellant 4,75 kg 100,00 4,75 9,50 1,83Adapters mass (including sep. mech.), kg 79,94 kg 0,00 0,00 79,94 15,44

Total wet mass (excl.adapter) 437,88 kgLaunch mass (including adapter) 517,82 kg

Table 3.1-1: Launch mass budget





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3.2 PGB Mass Budgets

3.2.1 Detailed Experiment Mechanics Mass Budget

Name No.Unit Mass

[kg]Total Mass

[kg]Margin

[%]Margin

[kg]

Total Masswith margin

[kg]

Inner Test Mass 1 10,000 10 0 0,00 10,00Outer Test Mass 1 10,000 10 0 0,00 10,00PGB Shaft 2,879 20 0,58 3,45

Mollette giunto 1 1 0,102 0,102Mollette giunto 2 1 0,071 0,071Mollette supporto piezo 1 1 0,098 0,098Mollette supporto piezo 2 1 0,030 0,03Assy supporto centrale 1 0,060 0,06Cilindro Giunto interno 1 1 0,161 0,161Cilindro Giunto interno 2 1 0,049 0,049Cilindro portante 1 1,082 1,082Piastre capacitive 1 1,164 1,164Piastrine capacitive 1 0,062 0,062

PGB Shell allocation (TBC) 1 7,60 7,60 20 1,52 9,12µmetal on PGB shell 1 1,76 1,76 20 0,35 2,11PGB interface spring 8 0,11 0,86 20 0,17 1,04Plasma shielding grid allocation 4 0,01 0,04 20 0,01 0,05Locking mechanisms allocation (TBC) 1 8,40 8,40 20 1,68 10,08Inch Worm 16 0,10 1,60 20 0,32 1,92

P A Y L O A D T O T A L S 43,14 10,7% 4,63 47,77

Table 3.2-1: PGB mechanics mass budget



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3.3 SVM Mass Budget

FUNCTIONAL SUBSYSTEM nr ass (kg) per uTotal Mass (kgMargin (%) Margin (kg) Mass (kg) with MarginStructure 104,61 18,09 18,92 123,53

Upper Platform 1 1,23 1,23 20,00 0,25 1,48Upper Cone 1 7,08 7,08 20,00 1,42 8,50

Outermost Cylinder 1 11,35 11,35 20,00 2,27 13,62Lower Cone 1 7,08 7,08 20,00 1,42 8,50

Lower Platform 1 1,23 1,23 20,00 0,25 1,48Cone to Cylinder I/F ring 2 14,58 29,16 20,00 5,83 34,99Cone to Platform I/F ring 2 4,03 8,06 20,00 1,61 9,67

PGB shell lock/unlock mech. 2 2,50 5,00 20,00 1,00 6,00Separation system ring 1 2,50 2,50 20,00 0,50 3,00

Miscellaneous (inserts. cleats. etc. 1 9,00 9,00 20,00 1,80 10,80Ballast mass 1 10,00 10,00 0,00 0,00 10,00

Payload support cone 2 4,80 9,60 20,00 1,92 11,52PGB interface 2 1,66 3,32 20,00 0,66 3,98

Thermal Control 8,70 20,00 1,74 10,44MLI thermal blanket 1 4,30 4,30 20,00 0,86 5,16

Paints & tapes 1 1,20 1,20 20,00 0,24 1,44Heating line 1 0,20 0,20 20,00 0,04 0,24

Doublers 1 2,00 2,00 20,00 0,40 2,40Miscellanea 1 1,00 1,00 20,00 0,20 1,20

Communications 9,60 10,00 0,96 10,56XPDN S-Band 1 1 3,60 3,60 10,00 0,36 3,96XPDN S-Band 2 1 3,60 3,60 10,00 0,36 3,96

RFDN S-Band 1 1,20 1,20 10,00 0,12 1,32S-Band Antenna 1 1 0,60 0,60 10,00 0,06 0,66S-Band Antenna 2 1 0,60 0,60 10,00 0,06 0,66Data Handling 16,00 20,00 3,20 19,20

CTU+RTU 1 16,00 16,00 20,00 3,20 19,20AOCS 5,92 13,11 0,78 6,69

Smart Sun Sensor 2 0,33 0,66 5,00 0,03 0,69Spin Rate Sensor 2 0,70 1,40 20,00 0,28 1,68

Spin Rate Sensor el. 2 0,90 1,80 20,00 0,36 2,16Magnetometer 3 0,19 0,56 5,00 0,03 0,58

Gyroscope 2 0,75 1,50 5,00 0,08 1,58Propulsion 37,66 13,95 5,26 42,92

EPS Assembly 2 9,27 18,54 20,00 3,71 22,25EPS Miscellanea 1 2,14 2,14 20,00 0,43 2,57

Nitrogen Thrusters 8 0,10 0,80 5,00 0,04 0,84Nitrogen Tank 2 7,19 14,38 5,00 0,72 15,10

Lines & Valves 1 1,80 1,80 20,00 0,36 2,16Power 57,68 14,82 8,55 66,23

Solar Array 2 13,91 27,82 20,00 5,56 33,38PCDU 1 13,50 13,50 10,00 1,35 14,85

Battery 1 16,36 16,36 10,00 1,64 18,00Harness 12,50 20,00 2,50 15,00

Power Harness 1 12,50 12,50 20,00 2,50 15,00Payload 55,34 12,77 7,07 62,41

Inner test mass 1 10,00 10,00 0,00 0,00 10,00Outer test mass 1 10,00 10,00 0,00 0,00 10,00

PGB Shaft 1 2,88 2,88 20,00 0,58 3,45PGB Shell allocation 1 7,60 7,60 20,00 1,52 9,12

ECE 1 5,40 5,40 20,00 1,08 6,48CPE 1 7,20 7,20 20,00 1,44 8,64

Locking Mechanisms allocation 1 8,40 8,40 20,00 1,68 10,08Inch Worms allocation 12 0,10 1,20 20,00 0,24 1,44

Plasma shielding grids allocation 4 0,01 0,04 20,00 0,01 0,05mumetal on PGB shell 1 1,76 1,76 20,00 0,35 2,11

PGB interface spring 8 0,11 0,86 20,00 0,17 1,04Propellant 4,75

Element 1 - Galileo Galilei

Table 3.3-1: SVM mass budget



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3.4 Propellant Mass Budgets

3.4.1 Attitude Control propellant mass budget

The attitude control has in charge the management of the rate damping and Sun acquisition after launcher separation, and satellite spin-up to initiate the scientific mission. Taking into account the proposed cold-gas assembly, the following total impulse budget has been computed: Rate damping+Sun acquisition : 30 Ns Holding phase before spin-up : 900 Ns Spin-up : 4600 Ns Total impulse : 5530 Ns Considering a specific impulse of 60s, the total propellant mass equals 9.4kg (9.5kg has been considered available, providing an additional total impulse of about 60Ns).

3.4.2 FEEP propellant mass budget

The propellant mass has been derived considering a simplified assembly (optimization will be still possible). Without FEEP failure : 2060 Ns (two years mission, each thruster) After one FEEP failure : 4065 Ns (two years mission, thruster) Total impulse : < 4500 Ns At the end, considering a two years mission, the propellant required for each thruster shall be compatible with a total impulse of 4500Ns each thruster.

3.4.3 CGPS propellant mass budget (alternative)

The propellant mass has been derived considering a simplified assembly (optimization will be still possible). Assembly : 13380Ns (two years mission) Considering a two years mission, the propellant required is 23kg (Isp=60s).



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4. MASS PROPERTIES

4.1 Centre of Mass, Direction cosines of the Principal Axes and Inertia Matrix

In the following, CoM, direction cosines and inertia matrix tables are provided, as follows.

for the full spacecraft in Table 4.1-1; for the spacecraft without the PGB assembly in Table 4.1-2; for the PGB assembly without the proof masses in Table 4.1-3; for the outer proof mass in Table 4.1-4; for the inner proof mass in Table 4.1-5

Table 4.1-1: Mass Properties for the full GG spacecraft



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Table 4.1-2: Mass Properties for the GG spacecraft without the PGB assembly

Table 4.1-3: Mass Properties for the PGB assembly without the proof masses



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Table 4.1-4: Mass Properties for the outer proof mass

Table 4.1-5: Mass Properties for the inner proof mass



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5. POWER BUDGET

5.1 System Power Budget

The power demand of the satellite is computed taking into account the design maturity of each unit (power contingency). The reference configuration used to compute the power budget includes the utilization of the FEEP organized in two clusters with 4 thrust each and assuming an average total thrust of 350 uN. The following table summarizes the satellite power consumption for the reference configuration.

Sunlit

No. Of active

Unit Power

[W]

Contingency [%]

Power with

Contingency[W]

Nominal Power

[W]

Nominal Power

[W]

LEOP phase

[W]

1 9 20 10.8 10.8 0 01 18 20 21.6 21.6 0 0

32.4 0.0 0.01 18.0 10 19.8 19.8 19.8 19.81 20.0 3 20.6 20.6 20.6 20.61 6.5 5 6.8 6.8 6.8 6.81 25.0 10 27.5 44.5 27.5 27.5- - - - 180.0 0.0 0.01 12.0 20 14.4 14.4 30.0 30.01 1.3 10 1.4 1.4 1.4 0.00 19.8 10 21.8 0.0 0.0 21.81 6.0 10 6.6 6.6 6.6 0.03 0.8 10 0.9 2.6 2.6 2.61 133.0 20 159.6 159.6 159.6 0.0

456.4 275.0 129.1

488.8 275.0 129.19.8 5.5 2.6

10.0 5.6 2.6

508.5 286.1 166.5GRAND TOTAL w/o system margin [W]

PCDU loss [2%]Harness loss [2%]

FEEP (2 cluster option)Total Service Module [W]

Total Satellite [W]

Fine Sun sensorGyroRate SensorMagnetometer

TRSP 2 (Tx + Rx)PCDUBattery (max charging)TCS (heaters)

CPETotal P/L [W]

CDMUTRSP1 (Tx + Rx)

Power Budget (Configuration with 2 FEEP clusters) Eclipse

Equipments

ECE

Table 5.1-1: Satellite Power Budget



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5.2 Payload Power Budget

Sunlit

No. Of active

Unit Power

[W]

Contingency [%]

Power with

Contingency[W]

Nominal Power

[W]

Nominal Power

[W]

LEOP phase

[W]

1 9 20 10.8 10.8 0 01 18 20 21.6 21.6 0 0

32.4 0.0 0.0CPE

Total P/L [W]

Power Budget (Configuration with 2 FEEP clusters) Eclipse

Equipments

ECE

Table 5.2-1: Payload power budget

5.3 SVM Power Budget

The following table summarizes the calculated power consumption of the SVM. For each unit the power contingency based on design heritage has been considered to estimate the power consumption.

Table 5.3-1: SVM power budget



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The Solar Array panels have been sized to sustain the load power demand of 509 W during the sunlit period, which includes 180 W required to recharge the battery, assuming a BCR efficiency of 95%.

The battery has been sized considering the power demand during the eclipse period of 288 W (including the BDR efficiency of 95%), and maximum DoD of 30%. The delivered power by the solar array at BoL and EoL (6 years) is reported in the table below.

Table 5.3-2: Power delivered by the solar array at BoL and after 6 years. To estimate the power consumption of the PCDU, the models in Figure 5.3-1 and Figure 5.3-2 have been used. The power loss due to the PCDU power distribution has been calculated as 2% of SC total power demand. The power loss due to the harness resistance has been calculated as 2% of SC total power demand plus PCDU power distribution loss.



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Figure 5.3-1: PCDU sunlight power consumption

Figure 5.3-2: PCDU eclipse power consumption

SA Regulator

Eff = 96%

BCR Regulator

Eff = 95%

Psa = 545 W

SA Regulator Electronic Consumption

Pe = 8,2 W 189 W

Pd = 22 W

Pd = 9 W

180 W To recharge the Battery

To supply the Loads

PCDU sunlight power consumption : Psun = 22 + 9 + 8.2 = 39.2 W

BDR Regulator

Eff = 95%

302 W

Pd = 9 W

288 W To supply the SC loads

Battery Regulator Electronic

Consumption Pe = 8,2 W

In Eclipse period: Peclipse = 14 + 8.2 = 22.2 W



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6. DATA RATE BUDGET

The mass memory budget and hence the telemetry data rates have been calculated on the basis of the following table.

Table 5.3-1: GG data rate budget



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7. RF LINK BUDGETS

Three main cases of RF link budgets, based on the architecture proposed in the Design Report, have been examined. Followings fixed parameters have been used as inputs:

• Malindi ground station EIRP in uplink and G/T in downlink • S-Band transponder output power = 23 dBm (200 mW) • RFDN losses • SP-L TM modulation • Reed-Solomon coding for TM • Galileo Galilei altitude = 520 km • Elevation over Malindi = 10 degrees • TC bit rate = 4 kbps • TC modulation index = 1.0 rad pk • Ranging uplink modulation index = 0.6 rad pk (where applicable) • TM modulation index = 1.1 rad pk • Ranging downlink modulation index = 0.5 rad pk (where applicable)

The parameters changed in the three cases listed here below are:

• LGA gain: o the minimum for data rate dimensioning o the maximum to verify that power flux density at the Earth limit is not exceeded

• Ranging mode • TM maximum information rate

o 450 kbps (that becomes 512 kbps after Reed-Solomon coding) for TM only o 225 kbps (that becomes 256 kbps after Reed-Solomon coding) for TM + RNG

In details:

• Case 1: TM only with LGA minimum gain • Case 2: TM + ranging with LGA minimum gain • Case 3: TM only with LGA maximum gain



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Case 1



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Case 2



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Case 3



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8. POINTING BUDGET

Taking into account the specificity of GG mission, only spin-axis pointing budget is relevant. Two budgets have been considered:

• at spin-up completion; • after one year mission with 1 failed FEEP thruster.

Error contributor Satellite spin axis error

[deg] Attitude determination error 1 Control error 0.5 Uncertainty on principal inertia frame attitude 0.5 Total de-pointing 2

Table 5.3-1: Spin axis pointing error at spin-up completion

Error contributor Satellite spin axis error [deg]

Attitude determination error 1 Control error 0.5 Uncertainty on principal inertia frame attitude 0.5 orbital plane precession 5 solar pressure 2.7 atmospheric drag 3.3 gravity gradient residual magnetic dipole 6(*) eddy current residual torque left by thrusters assembly 2 (**) Total de-pointing < 21

9.2 (rss) (*) allocation (**) no FEEP failure (allocation)

Table 5.3-2: Spin axis pointing error after one year mission with 1 failed thruster



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END OF DOCUMENT